public function UpdateLists()
 {
     $api = new MCAPI($this->apikey);
     $retval = $api->lists();
     if ($api->errorCode) {
         SS_Log::log("Unable to load lists()! Error Code = " . $api->errorCode . " Error Msg = " . $api->errorMessage, SS_Log::ERR);
         return false;
     } else {
         foreach ($retval['data'] as $list) {
             // Get DataList of All MCLists
             $dl = MCList::get();
             $l = $dl->where("ListID = '" . $list['id'] . "'")->first();
             // If the Current Iterations List Object Does Not Yet Exist, Create It
             if (!is_object($l)) {
                 $l = new MCList();
                 $l->setField("ListID", $list['id']);
             }
             // Populate/Overwrite the List Data
             $l->setField("Name", $list['name']);
             $l->setField("WebID", $list['web_id']);
             $l->setField("Subscribed", $list['stats']['member_count']);
             $l->setField("Unsubscribed", $list['stats']['unsubscribe_count']);
             $l->setField("Cleaned", $list['stats']['cleaned_count']);
             $l->write();
             // Add/Delete any New/Removed Merge Tags
             // (Newly Added Merge Tags Will Need Linking/Relating to the Appropriate DB Field Name
             // via Admin -> Setting -> MC Lists -> List Field Relationships)
             $retval = $api->listMergeVars($l->ListID);
             if ($api->errorCode) {
                 SS_Log::log("Unable to load listMergeVars()! Code = " . $api->errorCode . " Msg = " . $api->errorMessage, SS_Log::ERR);
                 return false;
             } else {
                 $currTags = array();
                 foreach ($retval as $mergeTagData) {
                     $currTags[] = $mergeTag = $mergeTagData['tag'];
                     $listField = $l->getComponents("MCListFields", "\"MergeTag\" = '" . $mergeTag . "'")->first();
                     if (empty($listField)) {
                         $lf = new MCListField();
                         $lf->setField("MergeTag", $mergeTag);
                         $lf->write();
                         $l->getComponents("MCListFields")->add($lf);
                     }
                 }
                 // Create DataList of All Existing MC List Fields Which Are No Longer Present In MailChimp (Old Merge Tags) and Delete Them
                 $dl = new DataList("MCListField");
                 $filter = "\"MCListID\" = '" . $l->ID . "' AND \"MergeTag\" NOT IN (" . $this->arrayToCSV($currTags) . ")";
                 SS_Log::log("Cleaning up historical merge fields. MCListField delete filter = '" . $filter . "'", SS_Log::NOTICE);
                 $dl->removeByFilter($filter);
             }
         }
     }
     return true;
 }